DCL-17-078, Request for Extension of Seismic Probabilistic Risk Assessment Submittal
| ML17249A431 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 09/06/2017 |
| From: | Franke J Pacific Gas & Electric Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| DCL-17-078 | |
| Download: ML17249A431 (3) | |
Text
Pacific Gas and Electric Company~
September 6, 2017 PG&E Letter DCL-17-078 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Jon A. Franke Vice President Generation Technical Services P.O. Box 56 Avila Beach, CA 93424 805.545.4888 E-Mail: JBFD@pge.com 10 CFR 50.4 1 0 CFR 50.54(f)
Request for Extension of Seismic Probabilistic Risk Assessment Submittal
Dear Commissioners and Staff:
On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued NRC letter, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident," to all power reactor licensees and holders of construction permits in active or deferred status, including Pacific Gas and Electric Company (PG&E). This letter directed the addressees to reevaluate the seismic hazards at their power plant site(s), including the Diablo Canyon Power Plant (DCPP), using present-day NRC requirements and guidance, and to identify actions to address plant specific vulnerabilities associated with the updated seismic hazards.
In response to the NRC request, PG&E performed a seismic hazard reevaluation for DCPP and developed a DCPP-specific ground motion response spectrum (GMRS) for screening purposes. These were submitted to the NRC on March 11, 2015, with a revision submitted on December 21, 2015. Based on the results of the screening evaluation, DCPP screened in for a seismic probabilistic risk assessment (SPRA),
which will include a high-frequency evaluation, and a spent fuel pool integrity evaluation.
On October 27, 2015, the NRC issued NRC Letter, "Final Determination of Licensee Seismic Probabilistic Risk Assessments Under the Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendation 2.1 'Seismic' of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident." This letter included required submittal dates for the SPRAs and A
member of the STARS Alliance Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek
Document Control Desk September 6, 2017 Page 2 PG&E Letter DCL-17 -078 remaining seismic evaluations. The DCPP SPRA submittal date was identified as September 30, 2017.
On December 21, 2016, the NRC issued NRC Letter, "Diablo Canyon Power Plant, Unit Nos. 1 and 2 - Staff Assessment of Information Provided under Title 10 of the Code of Federal Regulations, Part 50, Section 50.54(f), Seismic Hazard Reevaluations for Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident," providing their assessment of the updated seismic hazard reevaluation for DCPP. The assessment concluded that the "licensee's reevaluated seismic hazard is suitable for use in the other seismic assessments associated with the 50.54(f) letter."
In June 2017, an industry peer review of the DCPP SPRA, was performed by the Pressurized Water Reactor Owners Group. The Peer Review Team, in their draft report, concluded that "Diablo Canyon SPRA is judged by the review team to be technically adequate for supporting risk-informed applications and risk-informed decision making." The draft report also identified a number of Facts and Observations (F&Os). The disposition of the F&Os requires the performance of additional evaluations and preparation of updated SPRA documentation. The final Peer Review report is scheduled to be issued to PG&E by September 24, 2017.
Therefore, PG&E requests for an extension from September 30, 2017 to April30, 2018, for submitting the DCPP SPRA. This would allow PG&E to adequately address the F&Os via the Independent Assessment Team process described in Nuclear Energy Institute (NEI) Letter, "Final Revision of Appendix X to NEI 05-04/07-12/12-16, Close-Out of Facts and Observations (F&Os)," dated February 21, 2017.
The need for an extension was discussed with the NRC Staff via telephone on August 24, 2017.
PG&E plans to submit the Mitigating Strategies Assessment (MSA) for the reevaluated seismic hazards by April 30, 2018. The seismic hazard MSA will use the methodology described in Appendix H of NRC-endorsed NE112-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide," dated December 2016.
The spent fuel pool evaluation, which is separate from the SPRA evaluation, will still be submitted by the required date of December 30, 2017.
PG&E makes no new or revised regulatory commitments (as defined by NEI 99-04) in this letter.
A member of the STARS Alliance Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek
Document Control Desk September 6, 2017 Page 3 PG&E Letter DCL-17-078 If you have any questions or require additional information, please contact Mr. Hossein Hamzehee at 805-545-4720.
I state under penalty of perjury that the foregoing is true and correct.
Executed on September 6, 2017.
Vice President, Generation Technical Services mjrm/50702923 cc:
Diablo Distribution Brian Holian, NRC/NRR Director (Acting)
Scott A. Morris, NRC Region IV Administrator (Acting)
Chris W. Newport, NRC Senior Resident Inspector Balwant K. Singal, NRR Senior Project Manager Brett Titus, NRC Senior Project Manager A
member of the STARS Alliance Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek